A bad license game is a bad license game, but when a game is actually good, how much does having the official voice cast factor into your purchase?

Earlier today, Activision announced that Michael Rooker and Norman Reedus, who play the Dixon brothers in AMC's The Walking Dead show, will reprise their role for the upcoming Activision shooter. That got me thinking, how important is it to get the original voice actor to reprise their role in a licensed project? 

On the one hand, I feel like a good game is going to be good even if you don't get the original voice actor. Rare's GoldenEye 007 is considered one of the best lisenced titles of all time, and it didn't feature voice acting at all. Indiana Jones and the Fate of Atlantis was also a great adventure title and it didn't star Harrison Ford. Do we really need the original voice cast? 

However, it seems strange to me that video game companies get a license for a property and don't automatically have the voice actors onboard. I was throw off by the voice actor Sega got to play Tony Stark in its recent movie-based Iron Man games. I don't think anyone other than Robert Downey Jr. would have really worked. 

What do you think? Is it odd that voice actors sometimes don't want to reprise their roles in video games? Does that make video games seem like a lesser art?